1. Field of Invention
This invention relates to automotive engine speed control means, specifically backup manually activated throttle closure mechanisms.
2. Prior Art
The majority of state-of-the-art automotive engines employ an electronic module (ECM) to control engine operation. Electronic control of the power train provides optimum vehicle drivability, fuel economy and minimization of harmful exhaust emissions. These engines no longer have any mechanical connection between the accelerator pedal and the throttle valve. Power control is exclusively drive-by-wire, analogous to that of many current aircraft control systems. However, unlike commercial and military aircraft, automotive systems do not employ redundant means to reduce engine power should a malfunction such as engine speed runaway, occur due to several causes, such as:                Physical interference with the accelerator pedal itself by foreign objects such as floor pads, or impeded operation due to binding, wear and tear.        Intermittent quirks in software circuitry, such as stray electromagnetic interference, shorting by microscopic “whiskers” at solder joints on circuit boards, or control sensor anomalies.        Inadvertent overlapping of the accelerator pedal by the operator's foot when applying the brakes.        Simultaneous application of the brake and accelerator. Driver's use of the left foot for brake and right foot for the accelerator contributes to confusion or panic in an emergency.        
Since the problem has multiple possible causes of transient, intermittent nature, identification and elimination is difficult. This runaway phenomenon can be overcome by shutting off the ignition, or shifting the transmission into neutral. Employing the former shuts down the engine with consequent loss of braking and steering power boosts to the detriment of vehicle control. Shifting into neutral will curtail the runaway vehicle acceleration, but the engine RPM will increase due to the engine being unloaded further adding to the confusion and panic consequent to the situation. Neither of the foregoing remedies provide a satisfactory recourse for shortstopping this potentially catastrophic situation.
In comparison my invention offers an uncomplicated redundant manually actuated electromechanical means to override the Engine Control Module (ECM) and return the engine to idle speed without compromising other aspects of vehicle control. This override system is entirely independent of the vehicle primary propulsion and braking systems. It's high reliability is inherent due to its simplicity and straightforward interconnection with multiple electronic solid state control circuitry of the vehicle.